Coupling device for connecting a first workpiece to a second one

ABSTRACT

A connecting device for the connection of a first workpiece provided with at least one undercut longitudinal groove to a second workpiece which in turn is provided with a longitudinal groove or grooves has at least one extent which exceeds the width of the narrow cross-section of the longitudinal groove or grooves and at least one main body which can be partially fitted into the narrow cross-section of the longitudinal groove and which has longitudinal lateral shoulder surfaces extending on both sides of a ridge bar or the like central portion. At least one pin-like connection member which is adapted to be connected to the workpiece or the profile bar passes through the main body in the region of the ridge bar; outside the main body the connecting device is provided with a connection element for the other workpiece.

BACKGROUND OF THE INVENTION

The invention concerns a connecting device for the connection of a firstworkpiece—provided at least with one undercut longitudinal groove—to asecond workpiece which is in turn provided with a longitudinal groove orgrooves, wherein the connecting device is at least of an extent whichexceeds the width of the narrow cross-section of the longitudinal grooveor grooves; in particular the connecting unit is to be used in relationto profile bars of polygonal cross-section—preferably in relation toextruded profile members of rectangular cross-section—with longitudinalgrooves extending in the side walls of the profile members.

The specification of the applicant's DE-U 92 12 696 discloses a nut-likeelement as a connecting device, which in particular is used in relationto hollow profile members which are extruded from light metal and theinternal space of which is not accessible from the exterior. Thatpreviously known element is admittedly of a parallelepipedicconfiguration and has at least two mutually oppositely disposed flankwalls which are inclined at an angle, as well as a spring member whichon the one hand bears fixedly against one of the inclined flank wallsand which on the other hand engages with its free end over the narrowersurface of the element; in the relaxed condition of the spring that endis arranged at a spacing relative to the element. When the spring memberis pressed against the nut element, the latter can be readilyinserted—with its narrow side leading—into the groove of the undercutconfiguration.

The applicant's DE-U-297 17 089 also discloses for hollow profilemembers with longitudinal grooves which open towards the end of theprofile member, a connecting device in the form of a loop-shapedclamping connector which has loop limbs projecting approximately at aright angle at both ends from a base plate; at the transition of thebase plate, side slots on both sides delimit a central limb neckconfiguration. An angular clamping connector which is also describedtherein is provided at one end of a base plate with a loop limb whichprojects approximately at a right angle; in this case also side slots atboth sides delimit at the transition of the base plate a central limbneck configuration.

In consideration of those systems, it is the object of the invention toprovide a further fixing option for pairs of, in particular extrudedhollow profile members of polygonal—in particularrectangular—cross-section. The invention seeks to provide that thisconnecting device can be fitted quickly and easily and is verysubstantially resistant to rotation.

SUMMARY OF THE INVENTION

That object is attained by providing a connecting device for theconnection of a first workpiece provided with at least one undercutlongitudinal groove to a second workpiece which in turn is provided witha longitudinal groove or grooves, wherein the connecting device has atleast one extent which exceeds the width of the narrow groovecross-section of the longitudinal groove or grooves, in particular aconnecting device for profile bars of polygonal cross-section withlongitudinal grooves extending in the side walls of the profile members,characterised in that the connecting device has at least one main bodywhich can be partially fitted into the narrow cross-section of thelongitudinal groove and which has longitudinal lateral shoulder surfacesextending on both sides of a ridge bar or the like central portion,which in the region of the ridge bar has passing therethrough at leastone pin-like connection member which is adapted to be connected to theworkpiece or the profile bar, wherein the connecting device outside themain body is provided with a connection element for the other workpiece.The scope of the invention also embraces all combinations of at leasttwo of the features disclosed in the description and the drawing.

In accordance with the invention the connecting device has at least onemain body which can be partially fitted into the narrow groovecross-section of the longitudinal groove, with longitudinal lateralshoulder surfaces which extend on both sides of a ridge bar or the likecentral portion and which in the connecting position bear against theinside of shaped rib grooves, which main body in the region of the ridgebar has passing therethrough at least one pin-like connection memberwhich is adapted to be connected to the workpiece or the profile bar;the connecting device is additionally provided outside the main bodywith a connection element for the other workpiece.

In a preferred embodiment of the connecting device at least one of theends of its ridge bar, the main body is provided with a shoulder surfacewhich transversely connects the longitudinal lateral shoulder surfaces,as a support surface for a clamping block which can be fixed thereon.Its width and the width of the ridge bar are to correspond to the widthof the slot of the longitudinal groove—that is to say the region of thegroove which is not undercut—so that those parts of the connectingdevice can be introduced into same.

If there is a wish to connect to the one workpiece or profile member asecond workpiece with a—preferably central—bore-like passage, at a rightangle, then the pin-like connection member which projects from the ridgebar of the main body is introduced into that passage and fixed therein.

For that purpose, it has proven to be desirable for the connectionmember to be in the form of a screw pin with two screwthreaded regionswhich are preferably to be provided with opposite screwthreads and/orwhich are to be of different diameters. The latter measure facilitatesin particular orientation upon assembly; the screwthreaded region ofsmaller diameter is associated with the main body which affords thecorresponding screwthreaded bore. The same purpose can be served by themeasure of providing that the longitudinal-side shoulder surfaces extendin displaced relationship in respect of height by a distance in relationto the transverse shoulder surface or surfaces.

In accordance with the invention at least the screwthreaded region whichprojects outside the main body is provided with a self-forming thread sothat it can be firmly introduced into the counterpart workpiece in theevent of the counterpart workpiece having a smooth—that is to saythread-less—passage.

In order to permit movement of the clamping block in the longitudinaldirection of the connecting device, a guide leg for a groove of theclamping block projects from the transverse shoulder surface; the grooveis advantageously of an undercut configuration in cross-section and theguide leg is of a corresponding cross-section. However, the clampingblock can also be connected to the main body by a screw—which ispossibly provided in inclined relationship—and may have inclined cornerregions at its underneath surface, parallel to the longitudinal sideshoulder surfaces.

The two clamping blocks which are movable in the longitudinal directionof the workpiece or the profile bar engage into the longitudinal grooveof the profile bar and thereby provide a means for preventing rotationthereof. The element is pushed into the longitudinal groove of theprofile bar and fixed at the desired position by tightening the screwsin the clamping blocks. The described connection can be released at anytime and can be moved in the longitudinal direction of the secondprofile bar. In that situation, the two profile bars remain undamaged;the connection thereof does not involve any mechanical processingtreatment. The screw in the clamping block, by engaging into the guidebar of the main body, prevents it from falling out. When the screws arefirmly tightened however a bracing effect is produced in the groove ofundercut configuration. Inclined positioning of the screws in theclamping blocks is advantageous so that the pressure points are as closetogether as possible.

In another connecting device, in accordance with the invention, formedon the main body thereof at one end is a hammerhead-like insertionelement, by means of a neck which is on the center line of the mainbody; in this arrangement the spacing of the flank surfaces of thehammerhead from the center line is to be greater than the spacingthereof from the side edges of the main body. The hammerhead is insertedinto the undercut longitudinal groove in the workpiece which isassociated with the profile member or workpiece for receiving the mainbody.

It has proven to be desirable if in this case a screw pin passes throughthe main body, which screw pin can be inclined at an angle relative tothe surface of the main body. That screw pin should be inserted beneathor outside the underneath surfaces of the main body into a—alsoinclined—notch in the deepest part of the longitudinal groove whichaccommodates the main body; that notch is to be previously producedwithout any difficulty by means of an auxiliary tool and the positionthereof can be freely selected—depending on the respective factorsinvolved—upon assembly.

The screw pin, preferably a grub screw, is first screwed in after theconnecting device has been pivoted into position and is then between theshoulder surfaces which—as stated—bear against the inside of thelongitudinal groove. When the screw pin is tightened the connectingdevice is urged upwardly and at the same time with its steppedcross-section into the longitudinal groove of the profile member. Inthat procedure on the other hand the hammerhead pulls the second profilemember against the end face of the first profile member. A prerequisitein that respect is the above-mentioned provision of the notch at aprecise spacing relative to the end face at the deepest part of thegroove in the first profile member.

The scope of the invention also embraces a further design configurationin the form of a plate-like or strip-like main body through which, nearthe end faces thereof, passes at least one respective screw pin; theyare preferably inclined relative to each other, in which case theirtips—which engage into notches at the deepest part of the groove—arecloser to each other than their actuating ends which are above the mainbody. By virtue of that feature, a pulling force is applied to twoworkpieces or profile members with aligned longitudinal grooves whichjointly receive the main body, in other words, the end faces thereof arepressed against each other.

As already set forth above, the main body is inserted at the end intothe longitudinal groove of the first profile member and lightly fastenedwith the one screw pin. The second profile member is then fitted inaligned relationship at the end on to the first profile member, beingguided by the main body. The screw pins are now firmly tightened, inwhich case the main plate is urged upwardly into the groove in the twoprofile members and at the same time the two profile members are bracedagainst each other.

In this case also the notches are produced with a simple auxiliary tool;the screw pins are securely held therein.

The following have been found to constitute particular advantages of theconnecting system according to the invention:

no machining treatment required;

quick and easy assembly;

a connection which is force-locking and secured to prevent rotationalmovement;

potential compensation by virtue of notch edges;

no external damage to the profile member, and

subsequent installation is possible.

BRIEF DESCRIPTION OF THE DRAWINGS

Further advantages, features and details of the invention will beapparent from the description hereinafter of preferred embodiments andwith reference to the drawing in which:

FIG. 1 is a view in cross-section through an extruded hollow profilemember with fixing means arranged therein,

FIG. 2 is a partly sectional plan view of FIG. 1,

FIG. 3 is an end view of a part of a hollow profile member including aclamping connector and a side view of a second hollow profile memberassociated at a right angle therewith,

FIG. 4 is an end view of the clamping connector shown on an enlargedscale in relation to FIG. 3, with the main body and the ridge bar,

FIG. 5 is a plan view of the main body of the clamping connector withtwo clamping blocks of which one is withdrawn from the main body,

FIG. 6 shows a side view of the clamping connector with clamping blockfitted thereon,

FIG. 7 is an end view of the clamping block,

FIGS. 8 and 9 show a side view and an end view of another embodiment ofthe clamping connector,

FIG. 10 is a plan view of FIG. 8,

FIGS. 11 and 12 show a side view and an end view of a part of theclamping connector of FIGS. 8 through 10,

FIG. 13 is a plan view of FIG. 11,

FIGS. 14 and 15 show two different screw pins for the clampingconnector,

FIG. 16 shows an end view in relation to the structure of FIG. 15,

FIG. 17 is a side view of another clamping connector in two hollowprofile members which are shown in part and in cross-section,

FIG. 18 shows a plan view of the clamping connector shown in FIG. 17,

FIGS. 19 and 20 are views in cross-section through

FIG. 18 taken along lines XIX—XIX and XX—XX therein,

FIG. 21 is a perspective view of the clamping connector of FIGS. 17 and18,

FIG. 22 is a partly sectional side view of two axially connected hollowprofile members with a clamping element connecting them, and

FIG. 23 is a view in section taken through FIG. 22 along lineXXIII—XXIII therein.

DETAILED DESCRIPTION

An extruded hollow profile member 10 with cross-section axes A, B asaxes of symmetry which are passed through a central passage 12—whichprovides a female screwthread 11—of round cross-section of an insidediameter dl has in the middle of each of its profile side walls 14 arespective longitudinal groove 16 with a groove region 17 which is of anundercut cross-sectional configuration. The slot 18 of the longitudinalgroove 16, which is present in the surface of each of the side walls 14of the profile member, is of a width a of for example 8 mm and isdelimited at the surface 15 of the side wall 14 of the profile member bylateral shaped ribs 20 which extend in that side wall 14 as partsthereof, being of a thickness b of for example 4 mm.

The undercut groove region 17 is a channel-like opening over which theribs 20 extend, being approximately of triangular cross-section, of adepth n of for example 10 mm and of a maximum width e of here 22 mm, andin FIG. 1 at the inside of the ribs 20 affords an insertion path 24 of aheight h, which is delimited towards the deepest part 19 of the grooveby wall steps 22. The deepest part 19 of the groove is afforded by theoutside surface of the central tubular portion 12 of the hollow profilemember 10.

Fitted into the groove region 17 of undercut configuration, by way ofexample in FIG. 1, is a fixing unit 26 for a plate 28 comprising acaptive nut member 30 which is formed from a steel alloy, and a springtongue 32. The spring tongue 32 is fixed at one end to a flank surfaceof the captive nut member 30 and its free edge lies against the deepestpart 19 of the groove. The captive nut member 30 is held by a screw 36which passes through a central screwthreaded hole 34.

FIG. 3 is a diagrammatically simplified view showing the end face 13 ofa hollow profile member 10 to which a second hollow profile member 10_(a) is fixed at a right angle by means of a clamping connector 40 madefrom a steel material; the clamping connector 40 is inserted with abar-like main body 42 which is profiled to correspond to thecross-section of the longitudinal groove 16 into one of the undercutlongitudinal grooves 16; formed on the main body 42 which is adapted inrespect of cross-section by suitable corner regions 41 to the undercutgroove region 17 with inclined surfaces 19 _(a) on both sides and whichis for example of a width b of 18 mm and a length n of 40 mm is a narrowridge bar 43 of a width e₁ of about 10 mm, on the longitudinal center ofthe main body; the ridge bar 43 terminates at both ends at a spacing ffrom the end face of the main body 42. Provided in those spacing regionsand on both sides of the ridge bar 43 are shoulder surfaces 44 and 45respectively, wherein the lateral shoulder surfaces 45 are disposed by adistance k above the transverse shoulder surfaces 44 which are towardsthe end and which are therefore stepped.

The ridge bar 43 has a central screwthreaded bore 46 passingtherethrough, for a screw pin 48 with two screwthread regions 49, 49_(a) of different diameters d, d₁. The larger diameter di corresponds tothe inside diameter d₁ of the central tubular portion 12 of the hollowprofile members 10, 10 _(a) and is screwed in the tubular portion 12 ofthe hollow profile member 10 _(a).

Fitted on each of the shoulder surfaces 44 is a clamping block 50 of alength f—comprising a ridge bar 43 _(a) and a main plate 51 projectingin a wing-like configuration on both sides thereof—and is fixed by agrub screw 52 engaging into a screwthreaded bore 46 a in the shouldersurface 44; the screwthreaded bore in the clamping block 50 isidentified by reference 53. The cross-section of the clamping block 50is of such a configuration that—as FIG. 6 in particular shows—itsupplements the main body 42 and the ridge bar 43, in which respect itprojects somewhat beyond the latter with a height q of in this case 10mm.

A groove 54 of a slightly undercut configuration is provided on thelongitudinal center in the underneath surface of the main plate 51 inorder to be able to push the clamping block 50 on to a guide leg 56which is shaped out of the shoulder surface 44. The clamping block 50 isslid able on the longitudinal axis C of the main plate 51.

The two clamping blocks 50 which are movable in the longitudinaldirection of the hollow profile member 10 therefore engage into the slot18 of the longitudinal groove 16 of the hollow profile member or profilebar 10 and provide a means for preventing rotational movement. Theelement or the clamping connector 40 is now pushed into the longitudinalgroove 16 of the hollow profile member or profile bar 10 _(a) andsecured at the desired position by tightening the two screws 52 in theclamping blocks 50.

The connection can be released at any time and can be moved in thelongitudinal direction of the profile bar 10 _(a). Both hollow profilemembers or profile bars 10,10 _(a) remain undamaged as no mechanicalprocessing treatment is involved in making this connection. By virtue ofengaging into the guide leg 56 of the main body 42 the screw 52 in theclamping block 50 prevents it from falling out. When the screws 52 arefirmly tightened however there is a bracing effect in the undercutgroove region 17. Inclined positioning of the screw 52 in the clampingblocks 50 is advantageous so that the pressure points are as closetogether as possible. The inclined positioning is also advantageous interms of the assembly procedure.

The end regions of the screws 48, 52 can be of different configurations(pointed, flat, cylindrical or the like).

The drawing does not show that the clamping connector 40 can also beprovided with only one shoulder surface 44—and therefore with only oneclamping block 50 disposed at one end.

The clamping connector 40 in FIGS. 8 through 10 does not have theabove-described pairing 54/56. The length n of the clamping connector 40in this case measures about 40 mm, the width b is about 18 mm, the widthb₁ of the ridge bar 43 _(a) is here 10 mm and the length n₁ thereof isfor example 20 mm. The spacing n₃ of the screwthread bores 53 from eachother is then 30 mm with a diameter d₂ of 4 mm.

The screw pin 48 of the length t of in this case 30 mm in FIG. 14 isprovided in its two screwthreaded regions 49, 49 _(a)—of diameters d=M8and d₁=M 10—with mutually opposite screwthreads; the screwthread whichis the upper one in FIGS. 14 and 15 is self-tapping. In addition,provided in the end of the screwthreaded region 49 is a hexagonal recess58 of a width Z=SW4. The axial length t1 of the thicker screwthreadedregion 49 _(a) in this case measures 15 mm, while the length t₂ of acylindrical extension 36 in this case measures 4 mm with a diameter d₁of 8 mm.

In the embodiment of the screw pin 48 _(q) shown in FIGS. 15 and 16,provided between the screwthreaded regions 49, 49 _(a) of equal diameterd, d₁ is an intermediate portion 37 of a diameter d₃ of 6.5 mm. Thelength t₃ of that intermediate portion 37 measures 4 mm.

The two hollow profile members 10, 10 _(a) in FIG. 17 are held togetherby a clamping connector 60 which can be pivoted from the exterior intothe longitudinal grooves 16. It comprises a profiled strip 61 ofmaterial which, as shown in FIG. 20, comprises a main body 42 _(b) of awidth b with an underneath surface 62 which is curved in a partlycircular configuration in cross-section, and a ridge bar 43 _(b) whichis formed thereon and which is accompanied on both sides by shouldersurfaces 45, that is to say in cross-section it involves a steppedconfiguration.

The main body 42 _(b) has a screw hole 46 _(b) passing therethrough, theaxis Q of which is inclined at an angle w of about 45° relative to thesurface 64 of the ridge bar; an inserted screw pin 48 _(b) faces withits free end towards the adjacent hollow profile member 10 _(a) and canbe fitted into a notch 66 which has been previously impressed into thelowest part 19 of the groove by means of an auxiliary tool. Theinclinedly extending pin screw or screws or screw pin or pins 48 is orare screwed in only after the clamping connector 60 has been pivotedinto position.

The clamping connector 60 can be subsequently fitted into an existingstructure. The hollow profile member 10 is sawn to the precise length,notched on both sides and positioned between the other two hollowprofile members. The clamping connector 60 without the pin screw 48 _(b)is now pivoted into both profile members. The pin screw 48 _(b) isscrewed in and the profile member is joined in force-lockingrelationship. When two clamping connectors 60 of that kind are fixed toone end, that affords a configuration such as to prevent rotationalmovement.

Joined to the main body 42 _(b) by means of a neck 68 is a flathammerhead 70 as an insertion element with flank surfaces 71 which arecurved in the shape of part of a circle in cross-section and which areparallel to the axis and which go into side surfaces 72 which areinclined relative to the center line M of the clamping connector 60; theside surfaces 72 terminate at a front surface 73 which crosses thecenter line M. The spacing y of the flank surface 71 from the centerline M is larger than the spacing y thereof from the side edges 63 ofthe main body 42 _(b).

The neck 68 is symmetrical to the center line M in FIG. 21, but in FIGS.17, 18 and 19 it is curved at corner regions 69 which are in diagonalrelationship in cross-section.

When the screw pin 48 is tightened the screw connector 60 is urgedupwardly and at the same time urged with the above-mentioned steppedconfiguration in cross-section at the lateral shoulder surfaces 45 intothe longitudinal groove 16 of the first hollow profile member 10.

When the screw pin 48 _(b) is now firmly tightened the hammerhead 70pulls the second hollow profile member 10 _(a) against the end face 13of the first hollow profile member 10. A matter of substantialsignificance in regard to that procedure is the above-mentioned notch 66which extends inclinedly in the axial direction Q and which is formed ata precise spacing relative to the end face 13 in the deepest part 19 ofthe groove of the first hollow profile member 10. That is effected by asimple auxiliary tool and the screw pin 48 _(b) enjoys a secure hold.Moreover the 90° notch 66 is arranged at the same inclination as thescrew pin 48 and forms a support for same. Mechanical processingtreatment is not required with that kind of connection.

The clamping connector 60 _(a) in FIGS. 22 and 23 with two screw pins 48_(b) disposed at a spacing is intended to hold two axial hollow profilemembers 10, 10 _(a) together. It has a main body 42 _(a) whosecross-section approximately corresponds to that of the lower region inFIG. 4, with shoulder surfaces 45 extending on both sides of a ridge bar43, and inclined corner regions 41 which are provided beneath same. Theclamping connector 60 _(a) is fitted at the end into the longitudinalgroove 16 of the first hollow profile member 10 and lightly fastenedwith the one of the screw pins 48 _(b) near the end faces 49, after itengages approximately half over both hollow profile members 10, 10 _(a).

Then the second hollow profile member 10 _(a) is fitted with its endface 13—guided by the clamping connector 60 _(a)—on to the first hollowprofile member 10. The screw pins or holding screws 48 _(b) are nowfirmly tightened, in which case the clamping connector 60 _(a) is urgedupwardly into the longitudinal groove 16 of the hollow profile members10, 10 _(a) and in that case the two are braced relative to each other.

In this case also a notch 66 is previously formed at a precise spacingrelative to the end face 16 in the deepest part 19 of the groove in bothhollow profile members 10, 10 _(a); the screw pins 48 _(b) are securelyheld in the notches 66.

It will be appreciated that a plurality of those clamping connectors 60_(a) can be introduced into a plurality of grooves in the hollow profilemember 10 from the ends 13 thereof.

What is claimed is:
 1. A connecting device for the connection of a firstworkpiece provided with at least one undercut longitudinal groove to asecond workpiece which in turn is provided with a longitudinal groove orgrooves, and for the connection of profile bars of polygonalcross-section with longitudinal grooves extending in the side walls ofthe profile bars, wherein the connecting device has at least one extentwhich exceeds the width of a narrow groove cross-section of thelongitudinal groove or grooves of the second workpiece, wherein theconnecting device (40, 60, 60 _(a)) has at least one main body (42, 42_(a), 42 _(b)) which can be partially fitted into the narrow groovecross-section (17) of the longitudinal groove of the second workpiece(16) and which has longitudinal lateral shoulder surfaces (45) extendingon both sides of a ridge bar (43, 43 _(b)), which in the region of theridge bar has passing therethrough at least one connection member (48,48 _(b), 48 _(q)) which is adapted to be connected to the firstworkpiece or one of the profile bars (10,10 _(a)), wherein theconnecting device outside the main body is provided with a connectionelement (48, 48 _(b), 48 _(q); 70) for the second workpiece (10 _(a),10) wherein the main body (42), at least one of the ends of its ridgebar (43), has a shoulder surface (44) which transversely connects thelongitudinal lateral shoulder surfaces (45) as a support surface for aclamping block (50) which can be fixed thereon and has a width whichcorresponds to the width (e₁) of the ridge bar.
 2. A connecting deviceas set forth in claim 1 wherein the connection member (48, 48 _(q))which projects from the ridge bar (43) of the main body (42) is adaptedto be introduced into and fixed in a bore (12) of the first workpiece(10 _(a)) which is to be connected at a right angle.
 3. A connectingdevice as set forth in claim 1 wherein the connection member (48, 48_(q)) is a screw pin with two screwthreaded regions (49, 49 _(a)) whichare provided with a screwthreaded region of a smaller diameter thescrewthreaded region (49) is associated with the main body (42).
 4. Aconnecting device as set forth in claim 3 wherein at least onescrewthreaded region (49 _(a)) projects outside the main body (42) andis provided with a self-tapping thread.
 5. A connecting device as setforth in claim 1 wherein the longitudinal lateral shoulder surfaces (45)extend by a distance (k) with respect to the shoulder surface (44) ofthe main body (42).
 6. A connecting device as set forth in claim 1wherein a guide leg (56) for a groove (54) of a clamping block (50)projects from the transverse shoulder surface (44), wherein the groove(54) is of an undercut configuration in cross-section and the guide leg(56) is of corresponding cross-section.
 7. A connecting device as setforth in claim 6 wherein the clamping block (50) is supported on themain body (42) displaceably on a longitudinal axis (C) thereof.
 8. Aconnecting device as set forth in claim 6 wherein the clamping block(50) is connected to the main body (42) by a screw (52).